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Broiler stunning methods and their effects on welfare, rigor mortis, and meat quality. WORLD POULTRY SCI J 2019. [DOI: 10.1017/s0043933913000093] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Guijarro A, Mauri S, Aviles C, Peña F. Effects of Two CO 2 Stunning Methods on the Efficacy of Stunning and Blood Stress Indicators of Turkeys under Commercial Processing Conditions. J APPL ANIM WELF SCI 2019; 23:231-243. [PMID: 31415181 DOI: 10.1080/10888705.2019.1654384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The effect of CO2 gas-stunning methods (G1: 30% CO2 15 sec, 55% CO2 40 sec, 70% CO2 45 sec; G2: 30% CO2 15 sec, 80% CO2 85 sec) on the efficacy of stunning, blood stress indicators and meat quality of turkeys were assessed. A total of 375 turkeys (125 heavy males, 125 light males, and 125 light females) were used. After stunning, clinical parameters (posture-loss, wing-flapping, breathing, response to toe-pinching, eye movements, and palpebral, corneal and pupillary reflexes) and glucose, lactate and cortisol levels were assessed. The G2 method showed a higher percentage of correctly stunned birds (81.3 vs. 70.7%) and lower cortisol levels (0.44 vs. 1.22 g/dL). The weight and sex had a significant influence on the behavioral and physiological responses after stunning. The G2 method was found to be acceptable for animal welfare during stunning, based on both the percentage of animals correctly stunned and dead (92% to 100%) and the blood cortisol level after stunning.
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Affiliation(s)
- Angela Guijarro
- Animal Production Department, University of Cordoba, Cordoba, Spain
| | - Soledad Mauri
- Animal Production Department, University of Cordoba, Cordoba, Spain
| | - Carmen Aviles
- Animal Production Department, University of Cordoba, Cordoba, Spain
| | - Francisco Peña
- Animal Production Department, University of Cordoba, Cordoba, Spain
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Silva-Buzanello RAD, Schuch AF, Nunes Nogues DR, Falcão de Melo P, Gasparin AW, Sanches Torquato A, Canan C, Lourenço Soares A. Physicochemical and biochemical parameters of chicken breast meat influenced by stunning methods. Poult Sci 2018; 97:3786-3792. [PMID: 29982695 DOI: 10.3382/ps/pey281] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 06/11/2018] [Indexed: 11/20/2022] Open
Affiliation(s)
- Rosana Aparecida da Silva-Buzanello
- Departamento de Ciência e Tecnologia de Alimentos, Centro de Ciências Agrárias, Universidade Estadual de Londrina, Rodovia Celso Garcia Cid, Km 6, ZIP 86.057-970, Londrina, PR, Brazil
- Programa de Pós-graduação em Tecnologia de Alimentos, Universidade Tecnológica Federal do Paraná, Avenida Brasil 4232, Parque Independência, ZIP 85884-000, Medianeira, PR, Brazil
| | - Alexia Francielli Schuch
- Programa de Pós-graduação em Tecnologia de Alimentos, Universidade Tecnológica Federal do Paraná, Avenida Brasil 4232, Parque Independência, ZIP 85884-000, Medianeira, PR, Brazil
| | - Diego Ricardo Nunes Nogues
- Departamento Acadêmico de Alimentos, Universidade Tecnológica Federal do Paraná, Avenida Brasil 4232, Parque Independência, ZIP 85884-000, Medianeira, PR, Brazil
| | - Priscila Falcão de Melo
- Departamento Acadêmico de Alimentos, Universidade Tecnológica Federal do Paraná, Avenida Brasil 4232, Parque Independência, ZIP 85884-000, Medianeira, PR, Brazil
| | - André Wilhan Gasparin
- Cooperativa Agroindustrial Lar, Slaughter Supervision, BR-277, ZIP 85887-000, Matelândia, PR, Brazil
| | - Alex Sanches Torquato
- Departamento Acadêmico de Química, Universidade Tecnológica Federal do Paraná, Avenida Brasil 4232, Parque Independência, ZIP 85884-000, Medianeira, PR, Brazil
| | - Cristiane Canan
- Programa de Pós-graduação em Tecnologia de Alimentos, Universidade Tecnológica Federal do Paraná, Avenida Brasil 4232, Parque Independência, ZIP 85884-000, Medianeira, PR, Brazil
| | - Adriana Lourenço Soares
- Departamento de Ciência e Tecnologia de Alimentos, Centro de Ciências Agrárias, Universidade Estadual de Londrina, Rodovia Celso Garcia Cid, Km 6, ZIP 86.057-970, Londrina, PR, Brazil
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Siqueira TS, Borges TD, Rocha RMM, Figueira PT, Luciano FB, Macedo REF. Effect of electrical stunning frequency and current waveform in poultry welfare and meat quality. Poult Sci 2018; 96:2956-2964. [PMID: 28419361 DOI: 10.3382/ps/pex046] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 03/01/2017] [Indexed: 11/20/2022] Open
Abstract
This study aimed to evaluate the effects of different stunning frequencies and electrical current waveforms on chicken welfare and meat quality. Two-hundred-thirty-two Cobb broilers, 48 d of age and 2.76 ± 0.47 live-weight, were randomly assigned into 4 stunning treatments - 2 frequencies (300 Hz and 650 Hz) and 2 current waveforms (direct current [DC] and alternating current [AC]). Broilers were electrically stunned in a water bath in a commercial slaughterhouse (70 V, 100 mA). The electronarcosis and stunning efficiency were confirmed by assessment of visual parameters (absence of rhythmic breathing, ocular reflex, and coordinated wing flapping) and blood parameters (lactate, glucose, creatine kinase, sodium, and potassium), which were measured after bleeding. The incidence of traumas and injuries was assessed after plucking. Meat quality analysis was performed in Pectoralis major (PM), with determinations of pH, breast yield (PMY), water holding capacity (WHC), water absorption capacity (WAC), thawing loss (DL), cooking loss (CL), shear force (SF), and instrumental color (a*, b*, L*, C*, and h). The interaction between waveform and frequency was significant (P < 0.05) only for lactate, sodium, and lightness (L*). Lactate and sodium levels decreased at 300 Hz-DC. Meat lightness increased at 300 Hz-DC. The individual effect of frequency was significant for glucose, creatine kinase, potassium, WHC, PMY, b*, C*, and h. Regarding waveform, AC decreased plasma glucose and DC decreased creatine kinase and WAC. In general, stunning frequency exerts greater influence than waveform on the welfare and meat quality parameters of broilers. The use of frequency at 650 Hz proved to render animals efficiently unconscious and to promote greater meat quality.
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Mauri S, Guijarro A, Avilés C, Peña F. Influence of carbon dioxide stunning procedure on quality of turkey meat. Br Poult Sci 2017; 58:382-389. [PMID: 28117599 DOI: 10.1080/00071668.2017.1285393] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
1. The objective of this study was to evaluate the effect of sex and gas stunning on quality attributes of turkey breast meat. 2. One hundred B.U.T. Premium turkeys (50 males and 50 females) were divided into four groups of 25 animals and subjected to one of two CO2 stunning procedures: G1 stepwise (step 1: 30% CO2, 15 s; step 2: 55% CO2, 40 s; step 3: 70% CO2, 45 s) or G2 fixed concentration (80% CO2, 100 s). The pH and meat colour at 20 min post-mortem, and pH, colour (L*, a*, b*), water holding capacity (WHC), drip loss (DL), cooking loss (CL) and Warner-Bratzler shear force (WBSF) in breast samples at 24 h and 7 d post-mortem were assessed. 3. There were significant differences between stunning groups for pH, meat colour and CL, whereas no significant differences were found for DL and WBSF. Sex had a significant effect on pH and b* and ageing of meat affected pH, colour coordinates, DL and WBSF. 4. It was concluded that the G2 treatment affected negatively the pH value and colour coordinates. However, G2 stunning affected positively the WHC parameters. Female turkeys had better results than males for pH, and the colour of female turkey breast meat was less yellow than male breast meat.
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Affiliation(s)
- S Mauri
- a Departamento de Producción Animal , Universidad de Córdoba , Córdoba , Spain
| | - A Guijarro
- a Departamento de Producción Animal , Universidad de Córdoba , Córdoba , Spain
| | - C Avilés
- a Departamento de Producción Animal , Universidad de Córdoba , Córdoba , Spain
| | - F Peña
- a Departamento de Producción Animal , Universidad de Córdoba , Córdoba , Spain
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Salwani M, Adeyemi K, Sarah S, Vejayan J, Zulkifli I, Sazili A. Skeletal muscle proteome and meat quality of broiler chickens subjected to gas stunning prior slaughter or slaughtered without stunning. CYTA - JOURNAL OF FOOD 2015. [DOI: 10.1080/19476337.2015.1112838] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Farouk M, Al-Mazeedi H, Sabow A, Bekhit A, Adeyemi K, Sazili A, Ghani A. Halal and kosher slaughter methods and meat quality: A review. Meat Sci 2014; 98:505-19. [DOI: 10.1016/j.meatsci.2014.05.021] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 05/27/2014] [Accepted: 05/29/2014] [Indexed: 10/25/2022]
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Nakyinsige K, Sazili AQ, Zulkifli I, Goh YM, Abu Bakar F, Sabow AB. Influence of gas stunning and halal slaughter (no stunning) on rabbits welfare indicators and meat quality. Meat Sci 2014; 98:701-8. [PMID: 25089797 DOI: 10.1016/j.meatsci.2014.05.017] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 05/22/2014] [Accepted: 05/23/2014] [Indexed: 11/26/2022]
Abstract
This study assessed the effect of gas stunning which has not been conducted until now in comparison with slaughter without stunning on the welfare and meat quality of rabbits. Eighty male New Zealand White rabbits were divided into two groups of 40 animals and subjected to either halal slaughter without stunning (HS) or gas stunning using 61.4% CO2, 20.3% oxygen and 18.3 % nitrogen (GS). Analysis of the sticking blood revealed that both slaughter procedures caused a substantial increase in the levels of catecholamines, hypercalcemia, hyperglycemia, lactic acidemia and an increase in enzyme activities. The ultimate pH of the Longissimus lumborum muscle did not differ between treatments. GS exhibited higher lightness and cooking loss, and lower glycogen and MFI than HS. This indicates that both GS and HS can be significant stressors although the amount of stress may be below the threshold to negatively affect rabbit meat quality.
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Affiliation(s)
- K Nakyinsige
- Halal Products Research Institute, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; Department of Food Science and Nutrition, Islamic University In Uganda, 2555 Mbale, Uganda
| | - A Q Sazili
- Halal Products Research Institute, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; Department of Animal Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
| | - I Zulkifli
- Halal Products Research Institute, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; Department of Animal Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; Institute of Tropical Agriculture, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
| | - Y M Goh
- Institute of Tropical Agriculture, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; Department of Veterinary Preclinical Sciences, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
| | - F Abu Bakar
- Halal Products Research Institute, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; Department of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
| | - A B Sabow
- Department of Animal Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; Department of Animal Resource, Faculty of Agriculture, University of Salahaddin, Karkuk Street, Runaki 235 n323, Erbil, Kurdistan Region, Iraq
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Ylä-Ajos M, Tuominen S, Hänninen L, Ruusunen M, Puolanne E, Valros A. Gas composition in controlled atmosphere stunning affects turkey meat quality traits. Br Poult Sci 2012; 53:47-56. [DOI: 10.1080/00071668.2012.658025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- M Ylä-Ajos
- Department of Production Animal Medicine, University of Helsinki, Koetilantie 7, Helsinki, Finland.
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Xu L, Yue HY, Wu SG, Zhang HJ, Ji F, Zhang L, Qi GH. Comparison of blood variables, fiber intensity, and muscle metabolites in hot-boned muscles from electrical- and gas-stunned broilers. Poult Sci 2011; 90:1837-43. [PMID: 21753223 DOI: 10.3382/ps.2010-01331] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The aim of this study was to compare the effects of gas stunning (GS) and electrical stunning (ES) on energy metabolism in Arbor Acres broilers. Thirty-six birds were slaughtered without stunning (control) or after stunning with the following treatments: 40% CO(2) + 21% O(2) + N(2) (G40%); 60% CO(2) + 21% O(2) + N(2) (G60%); 35 V, 47 mA, 400 Hz (E35V); 50 V, 67 mA, 160 Hz (E50V); and 65 V, 86 mA, 1,000 Hz (E65V). Muscle samples were obtained from the pectoralis major (breast) and tibialis anterior (leg) muscles in ambient temperature within 45 min postmortem and stored at -80°C. Blood pH decreased consistently with GS (G40% and G60%) compared with ES and the control (P < 0.01). No consistent differences were observed between GS and ES in the plasma variables, glycolytic potential, adenosine phosphates, or fiber intensities. Plasma lactate increased with G40% and E35V (P < 0.05), whereas plasma uric acid and urea nitrogen increased with E35V (P < 0.05) compared with the control. Compared with the control, the intensity of type IIB fibers decreased in broilers stunned with E35V and E50V (P < 0.05) and glycolytic potential increased (P < 0.01) with G60% in the breast muscle and decreased (P < 0.01) in the leg muscle with all the stunning treatments except for E50V. Energy decreased (lower adenosine triphosphate, higher adenosine monophosphate, and adenosine monophosphate:adenosine triphosphate ratio, P < 0.05) in breast muscle with G40% compared with ES at high currents (E50V and E65V). However, the adenosine phosphates with GS were not significantly different (P > 0.05) from ES at low current (E35V) in either breast or leg muscle. In conclusion, no essential difference in energy metabolism was found in broilers stunned with ES and GS when ES was based on low current and high frequency and GS was based on hypercapnic moderate oxygenation. This study indicated that G40% was potentially a superior stunning variable.
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Affiliation(s)
- L Xu
- Key Laboratory of Feed Biotechnology of Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
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Werner C, Janisch S, Kuembet U, Wicke M. Comparative study of the quality of broiler and turkey meat. Br Poult Sci 2009; 50:318-24. [DOI: 10.1080/00071660902806939] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Werner C, Riegel J, Wicke M. Slaughter Performance of Four Different Turkey Strains, with Special Focus on the Muscle Fiber Structure and the Meat Quality of the Breast Muscle. Poult Sci 2008; 87:1849-59. [DOI: 10.3382/ps.2007-00188] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Linares M, Bórnez R, Vergara H. Effect of stunning systems on meat quality of Manchego suckling lamb packed under modified atmospheres. Meat Sci 2008; 78:279-87. [DOI: 10.1016/j.meatsci.2007.06.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Revised: 06/06/2007] [Accepted: 06/15/2007] [Indexed: 11/29/2022]
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Abeyesinghe SM, McKeegan DEF, McLeman MA, Lowe JC, Demmers TGM, White RP, Kranen RW, van Bemmel H, Lankhaar JAC, Wathes CM. Controlled atmosphere stunning of broiler chickens. I. Effects on behaviour, physiology and meat quality in a pilot scale system at a processing plant. Br Poult Sci 2007; 48:406-23. [PMID: 17701494 DOI: 10.1080/00071660701543089] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
1. The effects of controlled atmosphere stunning on the behaviour, physiology and carcase and meat quality of broiler chickens were studied experimentally in a pilot scale plant. 2. Gas mixtures tested were: single phase anoxic mixture (90% Ar in air, <2% O(2)); single phase hypercapnic anoxic mixture (60% Ar, 30% CO(2) in air, <2% O(2)); and biphasic hypercapnic hyperoxygenation mixture (anaesthetic phase, 40% CO(2), 30% O(2), 30% N(2); euthanasia phase, 80% CO(2), 5% O(2), 15% N(2)). 3. Anoxic stunning resulted in the least respiratory disruption, mandibulation and motionlessness, but most head shaking, leg paddling and twitching. Loss of posture occurred soonest with hypercapnic anoxia with the earliest and most twitching and wing flapping in individuals and earliest leg paddling. Biphasic birds were most alert, exhibited most respiratory disruption and mandibulation, and had the latest loss of posture and fewest, but longest bouts of wing flapping and least leg paddling and twitching. 4. Significant and sudden bradycardia and arrhythmia were evident with all gas mixtures and were not related solely to anoxia or hypercapnia. Birds stunned by Ar anoxia showed a slightly more gradual decline from baseline rates, compared with hypercapnic mixtures. 5. Few differences were found between gas mixes in terms of carcase and meat quality. Initial bleeding rate was slowest in biphasic-stunned birds, but total blood loss was not affected. Acceleration of post-mortem metabolism in anoxic-stunned birds was not sufficient to allow de-boning within 5 h without the risk of tough meat. 6. On welfare grounds and taking into account other laboratory and field studies, a biphasic method (using consecutive phases of anaesthesia and euthanasia) of controlled atmosphere stunning of broilers is potentially more humane than anoxic or hypercapnic anoxic methods using argon or nitrogen.
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Affiliation(s)
- S M Abeyesinghe
- The Royal Veterinary College, University of London, Hatfield, Hertfordshire, England
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Lin H, Sui SJ, Jiao HC, Jiang KJ, Zhao JP, Dong H. Effects of Diet and Stress Mimicked by Corticosterone Administration on Early Postmortem Muscle Metabolism of Broiler Chickens. Poult Sci 2007; 86:545-54. [PMID: 17297168 DOI: 10.1093/ps/86.3.545] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Three experiments were conducted to evaluate the effects of preslaughter physiological states mimicked by long- or short-term administration of corticosterone (CORT) and dietary energy sources on muscle glycogen contents and meat quality of broiler chickens. In experiment 1, the broilers were fed a high lipid diet (LD) or a normal diet (ND) that differed in carbohydrate (3.8%) and lipid (2.5%) contents from 21 d of age. From 28 d of age onwards, 50% of the chickens in each dietary treatment were subjected to CORT treatment (30 mg/kg of diet). At 7 and 11 d after CORT supplementation, musculus pectoralis major was sampled before and immediately after slaughter and analyzed for glycogen, pH, and R-value. In experiment 2, broilers, fed with the LD or ND diet from 21 d of age were subjected to 1 single s.c. injection of CORT (4 mg/kg of BW) for 3 h to mimicked acute stress at 46 d of age. In experiment 3, broiler chickens were supplied with water supplemented with glucose (30 g/L) for 1 wk before slaughter and were then subjected to the same CORT treatment as experiment 2. Blood and muscle samples were respectively obtained before and immediately after slaughter and analyzed for plasma glucose, urate and lactic acid, and muscle variables. Plasma concentrations of glucose and urate were significantly increased by acute CORT administration, whereas the lactic acid was not changed. Neither dietary energy source nor water glucose supplementation had any influence on the plasma variables. Dietary energy source or water glucose supplementation could not alter glycogen stores in musculus pectoralis major. Breast muscle glycogen stores were increased by stress mimicked by long-term CORT administration rather than by acute treatment. Preslaughter stress reactions had no relation to the depletion of breast muscle glycogen during the initial postmortem period. The initial breast muscle pH was significantly decreased by long-term CORT administration. The result suggests that short-term upregulation of circulating CORT is not involved in the elevated drip loss induced by preslaughter stress.
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Affiliation(s)
- H Lin
- Department of Animal Science, Shandong Agricultural University, Taian, 271018, PR China.
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Recent concerns about stunning and slaughter. Meat Sci 2005; 70:481-91. [PMID: 22063747 DOI: 10.1016/j.meatsci.2004.06.026] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2004] [Revised: 05/25/2004] [Accepted: 06/06/2004] [Indexed: 11/22/2022]
Abstract
This review summarises information that is relevant to concerns that have recently been expressed about stunning and slaughter. It is known that captive bolt stunning can result in brain material passing to the lungs via the jugular veins. If future studies show that BSE prions pass beyond the lungs to the edible carcass, there will be a move away from captive bolt stunning in large cattle towards electrical stunning. Greater use of electrical stunning in large cattle will increase the importance of blood splash in the beef industry. The theoretical causes of blood splash are reviewed to improve our understanding of this problem. In some situations it can be due to excessive venous pressure causing rupture of a capillary bed some distance from the source of the pressure rise, but it is not known whether this applies to electrical stunning. Gas stunning is replacing electrical stunning for poultry because it can reduce blood spots, which is a similar condition to blood splash. Several gas stunning methods are now being used, but it is not clear which of these is the most humane. Anoxic stunning leads to carcass convulsions and this causes more carcass damage. In fish, recent developments in electrical stunning are showing promise in overcoming problems with carcass damage. It is recommended that rock lobsters should be chilled or frozen before butchery, to ensure a humane death.
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